Frederick W J Cody

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The abilities of Parkinson's disease (PD) patients, taking routine medication, and of control subjects, to discriminate bilateral differences in the static angular positions of the two elbow joints were studied during passive (subject relaxed) and active (subject contracting to hold position) conditions. On each trial, one of the subject's elbows served as(More)
In separate experiments, we studied the temporal accuracy and precision of self-paced, repetitive finger-tapping in two groups of 12 patients with Parkinson's disease and a group of 12 controls matched to the patients with respect to age and general cognitive state. One group (I) of patients was studied initially following 12-15 h abstinence from normal(More)
1. The extent to which an active, human motoneuron pool can be inhibited via short-latency inhibitory pathways was studied by stimulating the common peroneal nerve and recording the inhibition of on-going soleus electromyographic (EMG) activity. The responses were compared at the same EMG level during walking and tonic voluntary activity to determine(More)
The ability of patients with Parkinson's disease (PD) and healthy subjects to synchronise finger tapping, produced by rhythmic wrist movements, with auditory signals of target frequencies (range 1-5 Hz) and to sustain such rhythms following sudden withdrawal of auditory cues was studied. Healthy subjects were able, in the presence of auditory cues, to(More)
Previous research has indicated that an early component of click-evoked myogenic potentials in the sternocleidomastoid muscle is vestibularly mediated, since it can be obtained in subjects with loss of cochlear function, but is absent in subjects with loss of vestibular function (Colebatch et al., 1994). We report here the results of an experiment to(More)
OBJECTIVE To investigate whether systematically adjusting the rate of auditory cues induces corresponding modulations of the temporal and spatial parameters of gait of patients with early-stage Parkinson's disease. DESIGN Subjects performed a series of 15 9-metre walks along a level floor under uncued and four cued conditions; the order of cued conditions(More)
The surface-recorded electromyographic (EMG) responses evoked in the ankle musculature by focal, transcranial, magnetic stimulation of the motor cortex were studied in healthy human subjects. Such soleus evoked motor responses (EMRs) were characterised over a wide range of background levels of motor activity and using different stimulus intensities. EMRs(More)
Using surface electromyography the reflex response of flexor carpi radialis elicited by forcibly dorsiflexing the wrist was compared with that elicited by applying vibration percutaneously to its tendon. This was done both in patients with Parkinson's disease and in normal subjects. The reflexes were elicited on top of a pre-existing voluntary contraction(More)
1. Stable extracellular unitary recordings were made from 138 cerebellar interpositus nuclear neurones (IPNs) in awake cats. Mean background discharge, in animals in a state of relaxed wakefulness and in the absence of overt movement, was 41.0+/-2.6 impulses/sec (mean+/-s.e.m).2. Animals were trained to accept a variety of sensory testing procedures without(More)
The effects upon the trajectories of practised slow (approximately 9 degrees/s) voluntary wrist-extension movements of applying vibration to the tendon of an antagonist muscle (flexor carpi radialis) during the course of the movement have been studied in patients with idiopathic Parkinson's disease and age-matched healthy individuals. In both patient and(More)